Namura .020 Over Bore Piston Kit Size C (47.46mm) for Yamaha 1993-01 YZ80 47.5mm

Piston Kit Size C (47.46mm) .020 Over Bore for Yamaha

This Namura .020 over bore piston kit size C (47.46mm) is a precision oversized piston assembly for Yamaha YZ80 models from 1993 to 2001, designed to restore cylinder compression after a 0.5mm overbore to 47.5mm.

Overview

This Namura .020 over bore piston kit size C (47.46mm) provides the next oversize option for Yamaha YZ80 engines needing a fresh bore to 47.5mm. Including a piston, rings, wrist pin, and circlips, the kit allows riders to extend engine life and maintain peak performance. It is a dependable choice for racers and enthusiasts rebuilding the YZ80 top end.

Built For Performance

• Cast from high‑silicon aluminum for thermal stability and reduced expansion
• Ring lands are machined to tight tolerances for optimal gas sealing
• Wrist pin features a phosphate coating for reduced wear
• Circlips are chamfered to ease installation and prevent dislodging
• Each piston is weight‑matched within the set for smooth operation

Fits These Machines

• for Yamaha YZ80 (1993‑2001)

On‑The‑Job Use

• Engine rebuilds after cylinder wear requires oversize pistons
• Motocross competition where consistent power delivery is critical
• Trail riding with high‑hour engines needing a larger bore refresh
• Restoration of classic Yamaha YZ80 models

Specs At A Glance

Good To Know

Q: Do I need to hone the cylinder before installing this piston? A: Yes, the cylinder must be professionally bored and honed to 47.5mm to match the 47.46mm piston, leaving proper clearance for expansion.

Q: Are the rings pre‑gapped for this size? A: Rings are not pre‑gapped; you must measure and file the end gaps per the service manual for the Yamaha YZ80 to avoid seizure.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.